WHAT IS A LIMITED LIABILITY COMPANY (LLC)?
LLC's are managed either by its members, or by managers elected or appointed by the members. That management structure is determined when the LLC is first formed, and is set forth in the Operating Agreement. That is a document roughly equivalent to corporate bylaws and partnership agreements.
An LLC's managing member, or any member who participates in operation of the LLC's business for more than 500 hours a year, is subject to self-employment tax on compensation received from the LLC.